A conventional pneumatic hammer generally includes a tubular member received in the body of the pneumatic hammer and a piston is reciprocatingly received in the tubular member. A hammer head is connected to the piston rod located out of the body of the pneumatic hammer so that when pressurized air enters into the tubular member via apertures defined through the tubular member, the piston is pushed to let the hammer head hit an object. After the piston is moved to its lower dead position, pressurized air will enter into the tubular member via another aperture through the tubular member and lift the piston to its higher dead position. Therefore, if the pressurized air continues to enter into the tubular member via the apertures, the piston is moved reciprocatingly to hit the object. It is important that the apertures are maintained to be opened so that pressurized air can enter the interior of the tubular member as desired to actuate the piston. Nevertheless, if the pneumatic hammer is put upside down, the tubular member could shift and the apertures could be blocked. The piston cannot be operated normally if the pneumatic hammer is used to hit an object located above the pneumatic hammer. Furthermore, the pneumatic hammer cannot cooperated with other tool such as a saw.
The present invention intends to provide a pneumatic hammer that prevents the apertures in the tubular member from being blocked when the pneumatic hammer is put upside down. A spring member is biased between a cap of the body of the pneumatic hammer and the tubular member so that the correct position of the tubular member is maintained with regardless of the orientation that the pneumatic hammer is put.